Boil elbows. When they are al dente, drain and rinse with warm water.
Put the elbows back in the big pot, add a stick to a stick and a half of butter or margarine.
Cut about two pounds of cheese into cubes about as big as
the end of your finger - mix the cubes in with the elbows and butter and it will start to melt. You want it to still have clumps of cheese though, not completely melted.
Take a small bowl and put in about a third of a cup of flour and add a
couple teaspoons of "Coleman's" Dry Mustard. Mix the flour and mustard together until it is a little golden color, but more
towards white than yellow.
Add some of the milk to the flour/mustard mixture to make a thick soupy consistency. Try to get all the lumps out!! You will probably use about half a can of the milk at this time. Pour this mixture into your elbows, butter, cheese pot and mix it up a little.
Now take about six eggs and break them into the bowl you mixed the flour/mustard in. Beat them a little, like you were going to scramble them. Using that bowl will insure that you get all the flour/mustard mixture into the casserole also breaking the eggs into a separate bowl, you won't be surprised with a bad egg in your elbows!! Now add the eggs to your pot and stir well. By this time, more of your cheese is going to be melted but you should still have quite a few chunks left.
Now get a large glass casserole dish and butter it (or spray with Pam, if you must!) - pour your stuff into this dish and let it sit for a few minutes. Now take the rest of the milk and pour it over the mac/cheese mixture. It should absorb down into your casserole, but if it doesn't, just poke it with a fork a little bit so it doesn't have milk just sitting on top - that might cause it to burn!
Cook at 350 for about an hour, maybe a little longer, 15 - 20 minutes, depending on how fast your oven cooks and how large your casserole is. If you make it smaller, lessen your cooking time.